Tony Blankley is worried. The normally cheerful editorial page editor of The Washington Times and “The McLaughlin Group” panelist is worried about Eurabia, about the possibility that radical Islamists will take over Europe. “If current birthrates continue,” he writes in “The West’s Last Chance,” “if current EU policies continue, if current multicultural sensibilities continue to deny Western institutions any protection and special respect, if current unthinking tolerance of the intolerant continues, if current thinking in Europe (and to a substantial extent in America) doesn’t change, Western values and lifestyles will be supplanted in Europe by the values of radical Islam.”

Mr. Blankley is not kidding. He starts the book with a scenario set in 2007 and 2008. Islamist demonstrators in London are calling for the end of display of the nude statue of Eros in Piccadilly Circus. Other Muslims start destroying statues and paintings in London, Florence, Rome, Madrid and Paris. Within months Britain, France and Germany establish commissions that recommend the removal of statues offensive to Muslims. Aluminum folds of cloth are put around Eros.

This is not so farfetched as you might think, as Mr. Blankley readily demonstrates. Europeans were happy to import Muslim immigrants to do their dirty work, and found themselves dependent on them as European birth rates dropped to record lows. But Europeans were unprepared for the surge of Islamism among the immigrants and their children. The natural instinct of a Europe ravaged twice in the 20th century by world wars has been to shun nationalism and exalt tolerance.

But, as Mr. Blankley writes, “Europe’s effort at cultural tolerance has slowly morphed into a surprisingly deep self-loathing of Western culture that has denied the instinct for cultural and national self-defense.” High Muslim birth rates mean that an increasing proportion of Europe’s population will be Muslim; the appeal of Islamism, espoused by only a minority of Muslims but tolerated and excused by a majority, has been growing. Europe, Mr. Blankley argues, is well on the road to becoming Eurabia. And Eurabia, he goes on, is something we should want to live with no more than Americans two generations ago wanted to live with a Europe dominated by Adolf Hitler.

So what can we do? Here the optimistic Tony Blankley emerges. If current trends continue, Europe becomes Eurabia; but as history shows us, “we can take it as a general principle that current trends rarely continue indefinitely.” The shocks of 2004 — the Madrid bombings, the massacre at Beslan, the assassination of Theo Van Gogh — have waked up many Europeans, in somewhat the same manner as September 11 waked up Americans; the London bombings last July came after he finished the manuscript. “Just as 2004 was the year that the man and woman in the European street and workaday politicians began to shift their thinking away from the grand old idea of a multicultural Europe, so, too, in the loftiest reaches of European universities and senior government bureaucracies, there is noticeable, even flagrant, doubt about the utility of multiculturalism and the underlying principles that have formed European policy and law as they relate to immigration and citizenship.”

Mr. Blankley asks: What would Franklin Roosevelt and Winston Churchill do? The answers will surely surprise the chattering class of today. Roosevelt promoted propaganda, imposed censorship, denaturalized citizens and deported them, interned citizens (not just the Japanese-Americans), restricted speech. Churchill imposed even stronger restrictive policies. The overwhelming majority of Americans and Britons and even of the chattering classes of the day supported them. They were emergency measures in a time of emergency. There was a war on.

“The West needs to recover its fighting faith,” Mr. Blankley writes and, in the case of Europe, its religious faith — which he thinks may be happening as the secular faith of multiculturalism is being undermined by events. He closes the book with specific recommendations. The United States should declare war on Islamic jihadists and enforce laws that prohibit the advocacy of the violent overthrow of the government. Our security forces should utilize ethnic profiling. We should secure our borders and adopt biometric national identification cards. We should do much more to develop Project BioShield, to hire translators fluent in Arabic and other relevant languages. We should be prepared for more military actions in the Middle East. We should try to strengthen Europeans’ belief in Western values and “win the European culture war.”

All this sounds like a tall order. But, Mr. Blankley argues, the alternative is dreadful. “If Europe becomes Eurabia, it would mean the loss of our cultural and historic first cousins, our closest economic and military allies, and the source of our own civilization. It would be a condition Americans should dread, and should move mountains to avoid.” It is comforting to believe that Islamism is no significant threat. Comforting to believe, yes, but very difficult to believe for anyone who has read “The West’s Last Chance.”

Michael Barone is a senior writer at U.S. News & World Report and co-author of “The Almanac of American Politics.”